Sockatume writes: The beleaguered MtGox bitcoin exchange has officially filed for bankruptcy in Tokyo, as reported in various news sources via AFP. According to the Wall Street Journal (paywalled; see The Verge for re-reporting) Bitcoin held an impromptu press conference that addressed recent rumours. They state that they have over $60m in liabilities against just $30m in assets, and confirm the loss of over $500m worth of Bitcoins, split between customers' balances (750,000 BTC) and company assets (100,000 BTC).

a weakness in the exchangeâ(TM)s systems was behind a massive loss of the virtual currency involving 750,000 bitcoins from users and 100,000 of the companyâ(TM)s own bitcoins. That would amount to about $425 million at recent prices.

The reactions of the various Japanese government officials are interesting. Essentially, there was no "theft" because Bitcoin is not a "real" currency.